Yamaha EF2400iS Generator will not run 13?500 AC

[santurinos]

We finally bought a Yamaha EF2400iS generator for our Trail-lite crossover 189QB with a standard Carrier 13?500 BTU A/C.
The camper and AC unit are 2008 model but never used before. We live in South West Georgia at 580 feet above sea level.
I did a search on Google and read many positive contributions about running a 13?500 RV unit with the EF2400iS.  I?ve read ?this generator will start a 13?500 BTU AC?, others say ?this generator will start most 13?500 BTU AC?

But the generator will not run the a/c unit, he will kick the overload after about 10 seconds.

I operate a AC service company and know about the problem with the starting load. This load is multiplies the regular running AMP draw from 14A - up to 45A.

I installed a hard-start to ease the compressor start.
Of course, EVERYTHING else is switched off including the converter (I installed an additional switch for the converter).
I also have a time delay installed to have the fan start up after the compressor (the blue wire for low cool on the Carrier Air V).
With other words, when the AC starts there is nothing else hocked up but the compressor.

The unit is working fine on shore power.

Do I have a bad generator?
Do you have the same problem with your Yamaha EF2400iS Generator?

We?re new in the RV-hobby and need your experience and help!

Y?ALL take care ? have a great day ? Walter and Dianne.

 

[Gary RV_Wizard]

I would not think the compressor start load would trip the internal protection on the Yamaha that fast, but ??? Will be interested to hear what other Yamaha 2400 owners say.

 

[donn]

Asked this on another forum and you did not answer, so here goes again.
Is the water heater on gas only, how about the refer?
My YG2800I runs my 15K BTU AC unit fins, so I suspect you still have something that is trying to run on ac when the generator is running.

 

[santurinos]

Dear Donn,
thank you for your replay, glad to have you on the net!
Donn, I've disconnected EVERYTHING, even the fan motor (just for a few seconds)


YES, I already installed the hard start (SPP6), I have about 10 of them in my service van...
I turned all the circuit breakers off except the main and the AC breaker.
We live at 587 feet above sea level in South West Georgia, altitude is not a problem here.

I installed an additional switch for the converter (12V DC ? 50Amps). The converter takes power from the 120V line to convert it to 12V DC. This 12V supply is used to charge the batteries and other circuits like water pump, lights and so on. You actually never know how much Amps he draws at the 120 V supply. It depends on the charge of the batteries. I measured the converter intake this morning, he took 2.84 Amps = about 280 watt.

I disconnected everything except the compressor. I even temporarily disconnected the AC fan motor for about 30 seconds, just to see whether the compressor would start (without the fan taking power from the generator) - no success!
I am able to choose the starting time for fan after the compressor is rev up (2 to 30sec.). The timer activates a conventional fan relay after the preset time, this will start the fan.

Before starting the AC, I measure 0.04A at 120V with running generator (phantom amps).

Hooked up on shore power, the AC takes about 35A by start up and then 9.8A running at about 80?F ambient. Just for your info, with lower temperatures in the morning, the AC will start up normally with my EF2400iS Generator, including the fan on low cool.

Afternoon with temperatures above 90? F, there is where the problems with the generator start on. FYI ? this generator does not have a ECO throttle.
Today afternoon it?s about 90? F. My generator is ON, everything is disconnected. While starting the AC on low incl. fan, I measure 33.6A on start up. After about 10sec. The overload on the generator disconnects the power.
I restart the generator after about 5 min. I disconnect the fan for the next attempt.
The clamp meter measures 29.8A, the compressor starts up. I connect the fan ? the AC is running this time, taking first 9.6A, then gradually increases to 12.1A.
It is a hit and miss situation. On my second try, it will not work again?

There are two options available:
a: replace the capillary tubes with a TXV (thermal expansion valve). This will reduce the power consumption at start up and will increase the performance of the AC unit!
b: Replace the compressor with a smaller one, like a 10?000 Btu. This will of course reduce the capacity of the unit, but it will at least start and cool when we need it!

I will replace the capillary tubes first, then? well the compressor will go too.

Thank you for all the positive input.
Y?ALL take care ? have a great day ? Walter and Dianne.

 

[dvredc5]

First off I'm not a a generator expert or electrician but I have had some experience with an undersized Honda generator in the past and now with our new RV that has 3 AC units and needs a 50 amps power circuit to operate them both.  We are very marginal with a 30amp circuit for 2 of the AC and with the monitoring gauge in the RV anything else running can overload the system and trip off the AC's.  I checked Yamaha's web site and from my limited knowledge it appears that this model generator is just barely adequate if not a little low on output to be able to do what you are asking of it.  According to their specs which I listed here it has a normal running capability of 2,000 watts continuous and  16.7 amps.  You can't look at the max listed because that short duration and under ideal conditions with cool temps and likely near sea level altitude.  Anything less than ideal and your performance (available watts and amps will be less.)  I'd check the model AC unit you have and see what the label states it draws when it starts up and then is running.  Either your AC unit draws more than you think or your Yamaha is not operating at full performance which could be something the dealer could check for you and possibly adjust.  With a smaller generator like this just being slightly out of proper adjustment could cause your problem.

Good luck 

MSRP* $1,479   


Type Brushless Inverter

Maximum AC Output 2400 watts

Rated AC Output 2000 watts

Rated / Maximum AC Current 16.7 / 20 amps @ 120V

Engine OHV, Air-Cooled, Four-Stroke, Single Cylinder

Displacement 171cc 

Overall Length 20.8 in

Overall Width 16.5 in

Overall Height 18.2 in

Dry Weight 75 lb

Fuel Tank Capacity 1.6 gal

Continuous Operation at 1/4 Rated Load 8.6 hr

Noise Level 53 - 58 dBA

Warranty 3 Years Limited Warranty
         

 

[Sarguy]

I went by this chart on the Yamaha site when I purchased my EF3000iSE. I wanted to make sure a 13,500 BTU A/C would have no problem since that was the main reason I wanted a generator.

http://www.yamaha-motor.com/outdoor/generator/application.aspx

 

[ttyR2]

My Yamaha EF2600e will start and run the Dometic AC unit in our Alpenlite....for about four minutes and then the switch/breaker trips on the generator. Next genset is going to be 3500w or bigger.

 

[santurinos]

A/C  and generator problem solved?

The Yamaha EF2400iS Generator will easily run my Carrier Air V - Standard 13.500 BTU A/C and the fridge and the TV.
The problem is the start-up procedure.

First of all, everything has to be disconnected respectively switched off before starting the A/C.

I installed an additional switch for the converter (12V DC ? 50Amps). The converter takes power from the 120V line to convert it to 12V DC. This 12V supply is used to charge the batteries and other circuits like water pump, lights and so on. You actually never know how much Amps he draws at the 120 V supply. It depends on the charge of the batteries, but it could take about 500 watts.

A hard start like the SPP6 is absolute necessary to ease the start up of the compressor.

With all of the above done, I could start the A/C sometimes, but many times the generator overload stopped it.

Upgrade you?re A/C:
I installed a fan delay circuit. When I turn the A/C ON (low cooling), the compressor starts immediately, but the fan comes on about 6 seconds after the compressor!
The fan motor takes about 10A for a short time at startup, together with the compressor about 35A. Depending on the weather (ambient temp) and the pressure at the high side of the compressor ? this may trigger the overload.
Run the fan on High speed for about 3 min. before starting the A/C
Start the A/C on LOW-cool and let it running for about 3 min. then you can switch to Hi-cool.

I have started my upgraded A/C at up to 98? F outside temp without any problems.
My Carrier A/C takes only about 1250W to 1500W on at Low-cool respectively 1350W to 1550W at high cool.
FYI: the low speed of the fan (fan only) is now controlled by the compressor start, it can not be turned on manually. The compressor will switch it on automatic. But the High speed is working normally. 
Of course, once the A/C is running, you may now turn the fridge and TV ON, everything that does not consume too much power (not the microwave)
PM me if you need more info about this upgrade.

Y?all take care, have a nice day ? walter and dianne

 

[Gary RV_Wizard]

Thanks for the report. I would not have guessed you would have to mod the a/c to make it work, but now we know.

 

[rodsterinfl]

Just a note to those reading this thread from 2010, there are/were two models of the Yamaha 2400 generator, the "IS" and the "ISHC". The ISHC replaced the IS and is designed to work with motors with a capacitor that assists in a 10-12 second boost to get motors going.